Apparatus and Method to Render Air Bag Inflators and Other Low Level Detonatable Devices Inert for Recycling

ABSTRACT

Detonable devices such as charged air bag inflators are fed to a shred tower at a controlled feed rate via a feed valve. Water spray and/or water baths in the shred tower prevent sparking and begin to solubilize chemicals while the inflators are fed to primary and optional secondary shredders respectively performing course and fine shreds. A sump receives the shredded material which continues to solubilize and separate chemicals from metal. A conveyor lifts solids from the sump. Dewatered solids are fed to a receiving box for metal scrap recycling.

RELATED APPLICATION

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 62/532,724, entitled Apparatus and Method to RenderAir Bag Inflators and other Low Level Detonatable Devices Inert forRecycling, filed on Jul. 14, 2018, the contents of which areincorporated herein by reference in their entirety for all purposes.

BACKGROUND Technical Field

This invention relates to metal and chemical recycling, and moreparticularly to an automated system for rendering air bag inflators andother low level detonatable devices inert for recycling.

Background Information

Air bag units for automobiles are widely used throughout the world. Theyare installed to protect passengers during a crash. Generally, an airbag unit comprises an air bag and an inflator therefor. Upon impact theinflator is actuated and releases gas to rapidly expand the air bag. Theinflated air bag forms a cushion between the passenger and, for example,the steering wheel to prevent the passenger from impacting against thesteering wheel as the automobile rapidly decelerates.

The inflator has a metallic housing. A gas generant, e.g., in the formof a chemical explosive propellant, is disposed in the housing alongwith an ignition means for igniting the propellant. The ignition meansmay be actuated by mechanical shock or by electrical signals generatedby suitable sensors.

Typically the housing for an air bag inflator is made of, for example,carbon steel, aluminum alloy and stainless steel. The propellant mayhave primary components such as NH₄NO₃ (ammonium nitrate).

When automobiles are scrapped, they are usually compressed. If anautomobile is compressed with an unused air bag unit therein, there isthe risk that the air bag unit will explode. In order to avoid thisrisk, the scrapping process is carried out only after actuation of theair bag inflator. The following disposal instructions may be provided toeffect actuation:

-   -   1. For electric air bag inflators a prescribed current is        applied by wires leading from a battery to actuate the inflator.        This may be accomplished either with the device in the car or        may be accomplished by removing, for example, the steering wheel        from the car.    -   2. For mechanical air bag inflators the inflator is removed from        the car, placed within scrapped or used tires and then        mechanically actuated.

While conventional approaches may be suitable for processing smallnumbers of air bag inflators, a need exists for an automated system andmethod for efficiently rendering large quantities of air bag inflatorsand other low level detonatable devices inert for recycling, such as toprovide manufacturers and automotive scrapping operations with theoption of shipping undeployed inflators to a third party for safedestruction and recycling.

SUMMARY

The appended claims may serve as a summary of the invention.

The features and advantages described herein are not all-inclusive andvarious embodiments may include some, none, or all of the enumeratedadvantages. Additionally, many additional features and advantages willbe apparent to one of ordinary skill in the art in view of the drawings,specification, and claims. Moreover, it should be noted that thelanguage used in the specification has been principally selected forreadability and instructional purposes, and not to limit the scope ofthe inventive subject matter.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention is illustrated by way of example and notlimitation in the FIGURE of the accompanying drawings, in which likereferences indicate similar elements and in which:

FIG. 1 is a schematic representation of an embodiment of the presentinvention, including optional variations thereof.

DETAILED DESCRIPTION

It should be understood at the outset that, although exemplaryembodiments are illustrated in the FIGURE and described below, theprinciples of the present disclosure may be implemented using any numberof techniques, whether currently known or not. The present disclosureshould in no way be limited to the exemplary implementations andtechniques illustrated in the drawings and described below.Additionally, unless otherwise specifically noted, articles depicted inthe drawings are not necessarily drawn to scale. In addition, well-knownstructures, circuits and techniques have not been shown in detail inorder not to obscure the understanding of this description. Thefollowing detailed description is, therefore, not to be taken in alimiting sense, and the scope of the present invention is defined by theappended claims and their equivalents.

General Overview

The present inventor has recognized that in order to recycle as scrapcertain devices that may or may not be deemed hazardous, such asaccording to one or both of DOT (U.S. Department of Transportation) orRCRA (Resource Conservation Recovery Act 1976) any chemicals must beseparated from the metal or plastics which are to be recycled. Thepresent inventor has also recognized that in many instances it would beinadvisable to batch feed detonable materials directly into a kiln oroven which is not designed to contain deflagrations or detonations. Theinventor further recognized that conventional shredding approaches wouldbe inappropriate for charged detonable devices due to the potential fordangerous detonations and inadequate separation of active chemicals fromshredded materials (e.g., metals).

The embodiments shown and described herein address these issues byshredding charged detonable devices, e.g., charged air bag inflators, ina continuous process within a special chamber while in contact withwater, e.g., via irrigation means such as a water spray/shower or bath,which reduces chances of sparking, eliminates heat buildup and begins toreact (hydrolyze) and dissolve the chemical constituents. Hydrolysis ofthe chemical constituents is completed in a water sump from which thesolids are then removed with a dewatering screw system. Water used forthe hydrolysis is then pumped off for hazardous wastedisposal/recycling. Optionally, the scrap content is then furtherprocessed in a high temperature kiln or oven to destroy any residue andrender the material inert/non-hazardous for scrap recycling.

The present inventor conducted a number of tests on sample devices tohelp devise and determine the effectiveness of the particulararrangement of elements shown and described herein to adequately renderinert various size air bag inflator devices and expose their chemicalcontents. As discussed in greater detail hereinbelow, particularembodiments are designed for continuously shredding batches of air baginflators or similarly combustible materials, along with cardboard boxesor other receptacles in which the bulk shipments of air bag inflatorsmay be transported. It should also be noted that the air bag inflatorsmay be shredded along with their associated fabric bag components.Embodiments include a closed chamber with rotary feeder and irrigationmeans (e.g., water bath or spray as shown) with a low speed dual stackedhydraulic shredder system that opens intact air bag units while beingirrigated by the irrigation means (e.g., under the water spray orsubmerged in a water bath) to provide for hydrolysis of the chemicalcontents. The material is then fed to a secondary irrigation means, suchas the water sump as shown, to complete the hydrolysis of the chemicalcontents. The metal shards are dewatered/separated from the hydrolysatee.g., using an inclined screw, and then staged in roll off boxes forrecycling. The metal scrap is optionally baked in an oven or kiln todestroy any remaining chemical residue prior to recycling. Embodimentsare configured to process approximately 80,000 to 180,000 pounds ofmaterial per day based on operation 24 hours per day.

Terminology

As used in the specification and in the appended claims, the singularforms “a”, “an”, and “the” include plural referents unless the contextclearly indicates otherwise. Although specific terms are employedherein, they are used in a generic and descriptive sense only and notfor purposes of limitation. All terms, including technical andscientific terms, as used herein, have the same meaning as commonlyunderstood by one of ordinary skill in the art to which this inventionbelongs unless a term has been otherwise defined. It will be furtherunderstood that terms, such as those defined in commonly useddictionaries, should be interpreted as having a meaning as commonlyunderstood by a person having ordinary skill in the art to which thisinvention belongs. It will be further understood that terms, such asthose defined in commonly used dictionaries, should be interpreted ashaving a meaning that is consistent with their meaning in the context ofthe relevant art and the present disclosure. Such commonly used termswill not be interpreted in an idealized or overly formal sense unlessthe disclosure herein expressly so defines otherwise.

Where used in this disclosure, the term ‘downstream’ refers to thedirection of flow of the material (e.g., boxes 12) through the apparatus5, such as indicated by arrows a in FIG. 1. The term ‘upstream’ refersto a direction other than downstream. When either term ‘downstream’ or‘upstream’ is used with reference to a component of apparatus 5, theseterms shall refer to the direction of flow of the material through suchcomponent.

Referring now to FIG. 1, embodiments of the present invention include anapparatus 5 for rendering inert and separating components of detonabledevices fabricated from metal and water soluble chemical explosivepropellants, for recycling. The apparatus includes a raw material feeder10, such as a conventional sorting table with or without rollers, a bin,and/or a hopper, for receiving material which may include the detonabledevices along with related components such as shipping material/boxes asdiscussed hereinbelow. As mentioned hereinabove, in particularembodiments, the detonable devices are charged air bag inflators withwater soluble chemical explosive propellants such as ammonium nitrate,nitroguanidine, and/or combinations thereof, although other propellantsmay be used. It should also be noted that air bag inflators may be ofsubstantially any form factor, including puck shaped metallic air baginflators typically used in automobile steering wheels, and cylindricalmetallic air bag inflators typically placed on the passenger-sidedashboard and elsewhere in the automobile. If the detonable devices aredelivered to the apparatus 5 in conventional boxes 12, such asfabricated from cardboard or similar materials used in the shippingindustry, such boxes may be placed on feeder 10 (e.g., a table as shown)and fed to conveyor 20. Alternatively, if the detonable devices aredelivered loosely in drums instead of in boxes, feeder 10 may take theform of a metering hopper fitted to feed the devices to conveyor 20. Itshould be recognized that the air bag inflators may be fed to conveyor20 along with associated components such as the actual air bags theinflators were designed to inflate.

A first conveyor 20, such as an inclined conveyor belt with buckets orcleats 22 as shown, is operatively engaged with a raw material feeder10, such as a roll table or hopper, to feed, at a controlled feed rate,the material/boxes 12, from the feeder 10 to an upstream portion of ashred tower 26.

Shred tower 26 is configured to convey the material in the downstreamdirection a therethrough, and includes a hopper 40, a primary shredder60 disposed within or downstream of the hopper 40, an optional secondaryshredder 62, shown in phantom, disposed downstream of the hopper 40, anda water sump 70 disposed downstream of the secondary shredder 62. Itshould be noted that in particular embodiments, hopper 40, as well asportions of shred tower 26 located downstream of the hopper, isfabricated from reinforced metal, e.g., steel plate of sufficient designstrength and volume to contain and allow safe venting of gases whilecontaining metal shards within the chamber in the event a detonation ofa detonable device occurs during processing. In particular embodiments,the hopper 40 and shred tower 26 is closed in 360 degrees about thedownstream direction, during shredding operations to preventshard/shrapnel release, as discussed in greater detail hereinbelow.Shred tower 26 is vented to atmosphere or to an emissions control deviceto prevent pressure buildup in the event of a detonation. The hopper mayalso include a hinged perforated plate cover (not shown). Moreover, afeed valve 30 is disposed at an upstream portion of the hopper 40, andis selectively actuatable between open and closed positions torespectively permit and prevent the material from entering the hopperfrom the conveyor 20, e.g., via a drop chute as shown. In particularembodiments, valve 30 is a rotary feed valve, such as a variable speedindexing rotary paddle wheel feeder, which introduces the material intothe hopper 40 at a controlled rate. The paddle wheel embodiment operatessimilarly to a revolving door in an office building to ensure that thevalve 30 is effectively closed immediately after each box 12 is fed intothe hopper 40, to help prevent shards or shrapnel from escaping duringshredding, e.g., should a detonation occur during shredding operations.It should also be recognized that in particular embodiments, the rate ofactuation of valve 30 will be coordinated with the speed of the conveyor20, such as by driving conveyor 20 with a variable speed motorcontroller by a processor, such as a conventional Programmable LogicController (PLC), or with a hydraulic motor drive, as will be discussedin greater detail hereinbelow.

Shred tower 26 is also equipped with an irrigation means, which inparticular embodiments includes a set of misting water spray nozzles 50disposed at an upper portion of hopper 40 to spray water, e.g.,continuously, in the hopper towards teeth of the shredder(s). Thisirrigation helps to prevent sparking and to begin to solubilize,separate, and hydrolyze the chemicals from the during operation of theprimary shredder 60 and/or secondary shredder 62. Optionally, theirrigation means may include a water bath, such as shown in phantomlines at 52′, within which one or both shredders 60, 62 may be immersed.Particular embodiments may also include one or more deluge water spraynozzles 52 communicably coupled to a flame detector for activation upondetection of a flame. The deluge water spray nozzles 52 are configuredto supply a high volume of water, (e.g., 25 gallons per minute or more)relative to the set of misting water spray nozzles 50 (e.g., 3-8 gallonsper minute).

Primary shredder 60 is configured to perform a course shred of thematerial, e.g., using relatively widely pitched teeth, including tearingopen the receptacles and releasing the detonable devices, while inparticular embodiments, optional secondary shredder 62 is configured toreceive the material from the primary shredder, and to perform a fineshred of the material using relatively finely spaced teeth, to open thedetonable devices and expose the chemical constituents. In particularembodiments, the primary shredder and optional secondary shredder eachincludes a 200 HP M100H shredder commercially available from SSIShredding Systems, Inc. of Wilsonville, Oreg., or a 200 HP shredderavailable from Komar Industries, Inc. of Columbus, Ohio, with thesecondary shredder having finer teeth than the primary shredder.

Water sump 70 is configured to receive and immerse the material from thesecondary shredder to continue to solubilize and separate the chemicalsfrom the metal. This tank also allows further hydrolysis activity tooccur with any water soluble chemicals. Reagents or other diluents maybe added depending on the chemical contents to further propagatedestruction. The tank may also include a level control and pumpingsystem to maintain water level. In particular embodiments, the watersump 70 has a capacity of at least about 500 gallons up to about 1000gallons.

A second conveyor 80 is configured to lift solids including shreds ofthe recyclables and the receptacles from the sump, wherein residualwater runs from the solids back to the sump to produce dewatered solids.In particular embodiments, conveyor 80 includes an inclined auger screwsuch as a dual floating screw dewatering system that pulls the scrapcontents, e.g., metal, fabric, and cardboard scraps, up and out of thesump 70 along an inclined trough while allowing the water/hydrolysate toreturn to the sump tank. The hydrolysate may then be removed from thesump for hazardous waste disposal/recycling.

Second conveyor 80 feeds the dewatered solids/scrap contents to areceiving box 90, from which the contents may be optionally fed to anincinerator, kiln or oven 110. Incinerator 110 may be provided with aconventional off-gas treatment system(s) operating at a temperatureadequate to destroy any chemical constituents to effectively burn anyremaining chemical residue and shreds of the receptacles 12, to leavemetal suitable for metal scrap recycling. In particular embodiments,incinerator 110 includes a rotary reactor incinerator configured tooperate at a minimum temperature of about 1000 F. In particularembodiments, the dewatered solids are fed by conveyor 80 to receivingbox 90 where they may be stored and/or tested for chemical contentpending introduction into the kiln or oven 110. If testing shows thatthe scrap is inert and non-detonable, then the scrap will be recycledwithout thermal processing with kiln 110.

Apparatus 5 may include one or more variable speed drives 92 operativelyengaged with the first conveyor and/or the second conveyor, andoptionally, with feed valve 30 and shredder(s) 60, 62. A processor, suchas a conventional PLC 100 is communicably coupled to the conveyors 20,80 and the shredders 60, 62, including the variable speed drive(s) 92,to control operation of the apparatus 5, such as to programmably controlfeed rates and timing of the various components 20, 80, 60, 62, etc. Forexample, the processor 100 is configured to actuate a variable speeddrive 92 of the first conveyor 20 to provide a controlled feed rate ofone receptacle 12 every 20 to 30 seconds.

Processor 100 may also be programmed to provide for cascading equipmentshut downs in the event of a jam or fire, as discussed hereinbelow. Forexample, apparatus 5 may include an electromagnetic detector 102 (e.g.,an ultra violet/infrared (UV/IR) detector) disposed within shred stack26, e.g., to detect flames, and/or to provide optical information to anoperator. Shred stack 26 may also include a hinged access door (notshown) within the closed chute extending between the primary shredder 60and the secondary shredder 62, to provide an operator with access toclear jams. At least one pressure sensor 104 may also be disposed inshred stack 26, e.g., in shredder(s) 60, 62, with both detectors 102 and104 communicably coupled via the processor 100 to the various componentsincluding the shredder(s) and conveyors and irrigation means 52, 52′ andspray 50. The processor is thus configured to alter operation of theapparatus in the event of a jam detected by the pressure sensor, and/orto increase water flow by sprayers 50, 52, in the event of a flame. Theprocessor may be configured to pause operation of components upstream ofthe jam until the jam is cleared, to reverse and then restart shreddingx times before stopping operation of the apparatus, and/or to signal anoperator of a jam. Sensor 102 may also serve as a camera to enable auser to view operation of the apparatus remotely.

A method for rendering inert and separating components of detonabledevices fabricated from metal and water soluble chemical explosivepropellants, for recycling, for example using a version of the apparatus5 shown and described hereinabove, will now be described as illustratedin the following Table I. As shown in Table I, the method 200 commenceswith receiving 210, with feeder 10, material including a plurality ofthe detonable devices. With first conveyor 20, the material is fed 212from the feeder to the upstream portion of shred tower 26 at acontrolled feed rate. The material is then conveyed 214 in a downstreamdirection through shred tower 26, via feed valve 30, which isselectively actuated at 216 between open and closed positions torespectively permit and prevent the material from entering the upstreamportion of the hopper.

Water is supplied 218 to hopper 40 via irrigation means 52, 52′, tosubstantially prevent sparking and to begin to solubilize and separatethe chemicals from the metal during operation of the primary shredderand/or the optional secondary shredder. Shredder 60 shreds the materialat 220, and optional secondary shredder performs a finer shred of thematerial at 222. The water sump 70 receives 224 the material from thesecondary shredder to continue to solubilize and separate the chemicalsfrom the metal. The second conveyor 80 lifts 226 the solids includingshreds of the metal from sump, wherein residual water runs from thesolids back to the sump to produce dewatered solids. The second conveyor80 then feeds 228 the dewatered solids to a receiving box for metalscrap recycling.

TABLE I Method 200 210 feeder receives material including detonabledevices 212 material fed from the feeder to upstream portion of shredtower 26 214 material conveyed in a downstream direction through shredtower 26 216 feed valve 30 selectively actuated between open and closedpositions 218 water supplied to hopper 40 via irrigation means 52, 52′220 Shredder 60 shreds the material 222 secondary shredder optionallyperforms a finer shred of the material 224 sump 70 receives materialfrom the secondary shredder 226 second conveyor 80 lifts the solidsincluding shreds of the metal from sump 228 second conveyor feeds thedewatered solids to a receiving box for metal scrap recycling

Although the foregoing description is directed towards automotive airbag inflators, those skilled in the art should recognize that theexemplary apparatus and method described herein may be applied to renderany number of low level detonatable devices inert for recycling.

Certain aspects of the present invention include process steps andinstructions described herein in the form of an algorithm. It should benoted that the process steps and instructions of the present inventioncould be embodied in software, firmware or hardware, and when embodiedin software, could be downloaded to reside on and be operated fromdifferent platforms used by real time network operating systems. Inaddition, the present invention is not described with reference to anyparticular programming language. It is appreciated that a variety ofprogramming languages may be used to implement the teachings of thepresent invention as described herein, and any references to specificlanguages are provided for disclosure of enablement and best mode of thepresent invention.

Modifications, additions, or omissions may be made to the systems,apparatuses, and methods described herein without departing from thescope of the disclosure. For example, the components of the systems andapparatuses may be integrated or separated. Moreover, the operations ofthe systems and apparatuses disclosed herein may be performed by more,fewer, or other components and the methods described may include more,fewer, or other steps.

Additionally, steps may be performed in any suitable order. It should befurther understood that any of the features described with respect toone of the embodiments described herein may be similarly applied to anyof the other embodiments described herein without departing from thescope of the present invention. As used in this document, “each” refersto each member of a set or each member of a subset of a set.

To aid the Patent Office and any readers of any patent issued on thisapplication in interpreting the claims appended hereto, applicants wishto note that they do not intend any of the appended claims or claimelements to invoke 35 U.S.C. 112(f) unless the words “means” or “step”are explicitly used in the particular claim.

Having thus described the invention, what is claimed is:

1. An apparatus for rendering inert and separating components ofdetonable devices fabricated from metal and water soluble chemicalexplosive propellants, for recycling, the apparatus comprising: a feederconfigured to receive material including a plurality of the detonabledevices; a shred tower configured to convey the material in a downstreamdirection therethrough, the shred tower including a hopper, at least oneshredder disposed within and/or downstream of the hopper, and a watersump disposed downstream of the at least one shredder; a first conveyoroperatively engaged with the feeder and the shred tower, the firstconveyor configured to feed the material from the feeder to an upstreamportion of the hopper at a controlled feed rate; a feed valve disposedat the upstream portion of the hopper, the feed valve being selectivelyactuatable between open and closed positions to respectively permit andprevent the material from entering the upstream portion of the hopper; airrigation means to substantially prevent sparking and to begin tosolubilize and separate chemicals from the metal during operation of theat least one shredder; the water sump configured to receive the materialfrom the at least one shredder to continue to solubilize and separatethe chemicals from the metal; a second conveyor configured to liftsolids including shreds of the metal from the sump, wherein residualwater runs from the solids back to the sump to produce dewatered solids;and the second conveyor configured to feed the dewatered solids to areceiving box for metal scrap recycling.
 2. The apparatus of claim 1,wherein the at least one shredder comprises a primary shredder and asecondary shredder, the primary shredder configured to perform a coarseshred of the material, and the secondary shredder configured to receivethe material from the primary shredder, and to perform a fine shred ofthe material.
 3. The apparatus of claim 1, wherein the irrigation meanscomprises a set of misting water spray nozzles configured to spray wateronto the at least one shredder, and/or a bath containing the at leastone shredder therein.
 4. The apparatus of claim 1, wherein the watersoluble chemical explosive propellants are selected from the groupconsisting of ammonium nitrate, nitroguanidine, and combinationsthereof.
 5. The apparatus of claim 4, wherein the detonable devicescomprise charged air bag inflators.
 6. The apparatus of claim 5, whereinthe charged air bag inflators comprise cylindrical metallic air baginflators and puck shaped metallic air bag inflators.
 7. The apparatusof claim 1, further comprising one or more variable speed drivesoperatively engaged with the first conveyor and/or the second conveyor.8. The apparatus of claim 7, wherein the first conveyor comprises acleated inclined conveyor belt.
 9. The apparatus of claim 7, wherein thesecond conveyor comprises an inclined auger screw.
 10. The apparatus ofclaim 7, wherein the material comprises receptacles containing theplurality of the detonable devices therein.
 11. The apparatus of claim10, wherein the one or more variable speed drives are configured toprovide the first conveyor with a controlled feed rate of 20 to 30seconds per receptacle.
 12. The apparatus of claim 10, wherein thereceptacles include cardboard boxes.
 13. The apparatus of claim 12,wherein the primary shredder includes relatively widely pitched teeth totear open the cardboard boxes, and the secondary shredder includesrelatively finely spaced teeth.
 14. The apparatus of claim 1, whereinthe hopper is closed in 360 degrees about the downstream direction andis constructed of metallic plate of at least ⅜ inches thick.
 15. Theapparatus of claim 2, wherein the feed valve comprises a rotary feedvalve.
 16. The apparatus of claim 15, wherein the feed valve is disposedin the closed position during operation of the primary shredder and/orthe secondary shredder to substantially prevent the material fromexiting the hopper via the upstream portion thereof during shredding.17. The apparatus of claim 26, wherein the water sump has a capacity ofat least about 500 gallons up to about 1000 gallons.
 18. The apparatusof claim wherein the incinerator comprises a rotary reactor incineratorconfigured to operate at a minimum temperature of about 1000 F.
 19. Theapparatus of claim 1, further comprising a camera configured to enable auser to view operation of the apparatus remotely.
 20. The apparatus ofclaim 3, further comprising one or more deluge water spray nozzlescommunicably coupled to a flame detector for activation upon detectionof a flame, the deluge water spray nozzles configured to supply a highvolume of water relative to the set of misting water spray nozzles. 21.The apparatus of claim 20, wherein the flame detector comprises a UV/IRflame detector.
 22. The apparatus of claim 2, comprising a closed chuteextending between the primary shredder and the secondary shredder, theclosed chute having a hinged access to permit user access to clear jams.23. The apparatus of claim 22, further comprising at least one pressuresensor operatively engaged with at least one of the primary shredder andsecondary shredder, the at least one pressure sensor communicablycoupled to a processor, the processor communicably coupled to the firstconveyor, the secondary conveyor, the primary shredder, and thesecondary shredder, the processor configured to alter operation of theapparatus in the event of a jam detected by the at least one pressuresensor.
 24. The apparatus of claim 23, wherein the processor isconfigured to pause operation of components upstream of the jam untilthe jam is cleared.
 25. The apparatus of claim 23, wherein the processoris further configured to reverse and then restart shredding x timesbefore stopping operation of the apparatus and signaling an operator ofa jam.
 26. The apparatus of claim 1, further comprising an incineratorconfigured to receive the metal from the receiving box to burn anyremaining chemical residue prior to recycling.
 27. An apparatus forrendering inert detonable devices such as charged air bag inflators forrecycling, the apparatus comprising: a feeder configured to receivecardboard boxes including a plurality of charged passenger sidecylindrical metallic air bag inflators and charged driver side puckshaped metallic air bag inflators, the inflators including ammoniumnitrate; a shred tower and a cleated inclined conveyor belt with avariable speed drive configured to bring the boxes from the feeder to atop of the shred tower at a controlled feed rate of 20 to 30 seconds perbox; a first feed hopper at the top of the shred tower; a primaryshredder disposed within the hopper; a rotary feed valve disposed withinthe hopper and configured to receive the boxes from the conveyor beltand to feed the boxes to the primary shredder for shredding; the rotaryfeed valve configured to close the shredder after receipt of the boxestherein to substantially prevent metallic shards from escaping duringsaid shredding; the hopper being closed on all sides and constructed ofmetallic plate and including a hinged perforated metallic plate cover;the hopper including continuous water spray nozzles aimed at shredderteeth to substantially prevent sparking and to wash chemicals from theinflators; the primary shredder having relatively widely pitched teethto tear open the boxes; a secondary shredder disposed below the primaryshredder and configured to receive the torn boxes and contentstherefrom; the secondary shredder having relatively finely spaced teeth;the hopper including a CCTV camera to view operation remotely, and aUV/IR flame detector connected to a secondary water deluge nozzle to beactivated upon detection of a flame; a closed chute between the twoshredders with a hinged side access door above the secondary shredder toclear jams; a water sump of 500 to 1000 gallon capacity disposed belowthe secondary shredder, and equipped with a high capacity pump feedingto a storage tank; a dual inclined auger screw configured to lift solidsincluding metal and cardboard scraps from sump, wherein residual waterruns from the solids back to the sump; the shredders including pressuresensors configured to stop the units if a jam occurs, to auto-reverse,and then restart shredding x times before signaling an operator of ajam; and a programmable logic controller (PLC) configured to operate theconveyor belt, the primary and secondary shredders, and the auger screw,and configured to pause operation of components upstream of the jamuntil cleared; the auger screw configured to feed the dewatered metalsolids to a rotary reactor incinerator feed pit operating at a minimum1000 F temperature to destroy any remaining chemical residue andcardboard from box shredding, to leave metal suitable for shipping tometal scrap recyclers; wherein the apparatus provides a low speed dualstacked hydraulic shredding operation to open the inflators under acontinuous water spray and expose the ammonium nitrate to a water bathto solubilize it and separate it from the metallic components.
 28. Amethod for rendering inert and separating components of detonabledevices fabricated from metal and water soluble chemical explosivepropellants, for recycling, the method comprising: (a) receiving, with afeeder, material including a plurality of the detonable devices; (b)conveying the material in a downstream direction through a shred towerincluding a hopper, at least one shredder disposed within and/ordownstream of the hopper, and a water sump disposed downstream of the atleast one shredder; (c) feeding, with a first conveyor operativelyengaged with the feeder and the shred tower, the material from thefeeder to an upstream portion of the hopper at a controlled feed rate;(d) selectively actuating a feed valve disposed at the upstream portionof the hopper, between open and closed positions to respectively permitand prevent the material from entering the upstream portion of thehopper; (e) irrigating with irrigation means, to substantially preventsparking and to begin to solubilize and separate chemicals from themetal during operation of the at least one shredder; (f) shredding thematerial with the at least one shredder; (g) receiving, in the watersump, the material from the at least one shredder to continue tosolubilize and separate the chemicals from the metal; (h) lifting, witha second conveyor, solids including shreds of the metal from sump,wherein residual water runs from the solids back to the sump to producedewatered solids; and (i) feeding, with the second conveyor, thedewatered solids to a receiving box for metal scrap recycling.
 29. Themethod of claim 28, wherein the at least one shredder comprises aprimary shredder and a secondary shredder, and said shredding (f)further comprises using the primary shredder to perform a coarse shredof the material, and using the secondary shredder to receive thematerial from the primary shredder, and to perform a fine shred of thematerial.
 30. The apparatus of claim 28, wherein the irrigation meanscomprises a set of misting water spray nozzles configured to spray wateronto the at least one shredder, and/or a bath containing the at leastone shredder therein.